Rotatable Dipoles/cushcraft 402CD
David L. Thompson
thompson@mindspring.com
Mon, 03 Feb 1997 06:47:55 -0500
N6BT wrote:
My comment: Lots of good information on the various products. I used the
Create
80 as part of a small beam with a square dipole as the driven element fed
HB9CV style.
The weak part of the antenna was the Create altho as long as power was below
1200W
there was no problem. 70' was just not quite high enough, too altho only
being 1S unit below
K4JPD on the UA9/JT (5/7 he 5/8) showed that I just needed it higher.
Create element finally went so its in my basement stored now. Maybe the
Force 12 dipole might be the thing! I set the dipole as a reflector and
only try to work 60 to 80Khz around 3.8Mhz.
My comments on the following:
>MOSLEY: Always liked this one in it's day, except for the weight. Center
loading
>is usually looked upon as being less efficient than loading farther out;
>however, the advantage is that the coil can be LARGE and, therefore, higher Q
>(more efficient). My guess is that it is as efficient as smaller coils farther
>out. Structurally strong. Was not as effective as linear loading in
pile-ups and
>contests.
The Mosley 2el 40 was better than the Linear loaded 2el Hy-gain (both at 80'
on many tests with both of us being 2 miles apart). The black insulators
kept breaking. Sold it to K4PI for spare parts.
>
>CUSHCRAFT: These are loaded farther out using fairly small diameter coils.
Have
>used several, both single and in the 2 element. The efficiency is much less
than
>linear loaded designs ("much" meaning 1 to maybe 2dB). Although it is as N4KG
>says, "A simple solution", the outboard coils are restricted to a small
>diameter, which means low Q. Have seen computer models of these elements
and of
>the 2 element Yagi. For maybe a little longer assembly time, the linear loaded
>is much better (whoever makes it).
The Cushcraft is light years ahead of Mosley or Hy-gain. Mine has worked so
well that N4KG and others put one up. N4KG said it was a killer...I was the
first USA 4 to 7O8 and 3Y0PI said I was the loudest W on 40 SSB. One local
had the KLM 4 el at 90' and I beat him in EVERY pile-up. Not only that but
it works great on 17 (333 countries), K1MM uses his on 12, and it works as
well as most verticals on 160!!!!!!!!!!!!!!!!! (Don't push it past 500 or
600W however).
I did use the 40 meter add element to TA-36 years ago and agree its better
than most non- rotatable dipoles and inverted V's at the same or lower height.
Dave K4JRB
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